title: Polymorphic patterns of pfcrt and pfmdr1 in Plasmodium falciparum isolates along the Thai-Myanmar border.
abstract: OBJECTIVE
  To investigate the distribution and patterns of pfcrt and pfmdr1 polymorphisms in Plasmodium falciparum (P. falciparum) isolates collected from the malaria endemic area of Thailand along Thai-Myanmar border.
  
  
  METHODS
  Dried blood spot samples were collected from 172 falciparum malaria patients prior received treatment. The samples were extracted using chelex to obtain parasite DNA. PCR-RFLP was employed to detect pfcrt mutation at codons 76, 220, 271, 326, 356 and 371, and the pfmdr1 mutation at codon 86. Pfmdr1 gene copy number was determined by SYBR Green I real-time PCR.
  
  
  RESULTS
  Mutant alleles of pfcrt and wild type allele of pfmdr1 were found in almost all samples. Pfmdr1 gene copy number in isolates collected from all areas ranged from 1.0 to 5.0 copies and proportion of isolates carrying>1 gene copies was 38.1%. The distribution and patterns of pfcrt and pfmdr1 mutations were similar in P. falciparum isolates from all areas. However, significant differences in both number of pfmdr1 copies and prevalence of isolates carrying>1 gene copies were observed among isolates collected from different areas. The median pfmdr1 copy number in P. falciparum collected from Kanchanaburi and Mae Hongson were 2.5 and 2.0, respectively and more than half of the isolates carried>1 gene copies.
  
  
  CONCLUSIONS
  The observation of pfmdr1 wild type and increasing of gene copy number may suggest declining of artesunate-mefloquine treatment efficacy in P. falciparum isolates in this border area.
authors.affiliation: Chulabhorn International College of Medicine, Thammasat University, Patumthani, Thailand.
authors.forename: Phunuch
authors.initials: P
authors.lastname: Muhamad
authors.forename: Wanna
authors.initials: W
authors.lastname: Chaijaroenkul
authors.forename: Papichaya
authors.initials: P
authors.lastname: Phompradit
authors.forename: Ronnatrai
authors.initials: R
authors.lastname: Rueangweerayut
authors.forename: Pongsri
authors.initials: P
authors.lastname: Tippawangkosol
authors.forename: Kesara
authors.initials: K
authors.lastname: Na-Bangchang
mesh_terms: D001769:Blood / Q000469:parasitology; D003062:Codon; D016054:DNA, Protozoan / Q000235:genetics / Q000302:isolation & purification; D018628:Gene Dosage; D006801:Humans; D016778:Malaria, Falciparum / Q000469:parasitology; D026901:Membrane Transport Proteins / Q000235:genetics*; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics*; D002052:Myanmar; D010963:Plasmodium falciparum / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D015800:Protozoan Proteins / Q000235:genetics*; D013785:Thailand
chemical_list: D003062:Codon; D016054:DNA, Protozoan; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D015800:Protozoan Proteins; C513498:Mdr1 protein, Plasmodium falciparum; C416369:PfCRT protein, Plasmodium falciparum
keywords: Gene copy number; Gene mutation; Multidrug resistance; Pfcrt; Pfmdr1; Plasmodium falciparum